If you want to truncate instead of round, this will work:

lnx = 123.456789012
?lnx - MOD( lnx, .0001) && Returns 123.456700000

>I have a series of numbers with up to 9 significant digits after the decimal point and would like to truncate the character values down to 4 significant digits.
>
>For example I have the following two values:
>
>123.456789012
>98.765432109
>
>I want to return these values:
>
>123.4567
>98.7654
>
>I can write a function to use something like ATC() to find the decimal point but is there a better way? Sergey, you will no doubt have something interesting and insightful so thanks in advance...:>)